This invention relates to an automatic supplying device of mechanical fasteners such as screws, bolts, rivets and the like.
Various types of devices have been heretofore known for automatically supplying mechanical fasteners such as screws, bolts, rivets, pins and the like (hereinafter termed screws) to desired positions. For instance, a hopper-vibrator type device has a fan-shaped comb vibrator that vibrates vertically in a hopper for delivering screws in a mutually aligned state with the heads held upward. A vibrating hopper type device delivers screws in such an aligned state with heads held upward under the effect of the vibrating hopper. Otherwise, a feeder vibrating type device utilizes a circular or rectilinear parts feeder, while a pipe feeder type device supplies screws to desired positions through pipes, and a suction delivery type device delivers the aligned screws in a vacuum-sucking manner.
However, in order to maintain the screws in a mutually aligned state with the heads held upward as described above in all of these devices, the following relation must be ordinarily maintained between the diameter D of the head and the length I of the screws. EQU I.gtoreq.1.3 D
Unless the above described condition is satisfied, the realization of the head-upward alignment of screws becomes difficult because of clogging caused at the comb-shaped vibrator in the hopper or in the parts feeder due to the irregular orientation of the screws. In the pipe feeder type device, the conveyance of screws becomes difficult because of clogging in the pipe caused by the irregular orientation. Even in a case where the condition of I.gtoreq.1.3 D is satisfied, screws having flat heads or flanged heads are easily brought into a state where the heads overlap with each other after the screws have been mutually aligned with the heads held upward, thus causing various problems in the conveyance or delivery of the screws.